Systemic lupus erythematosus (SLE), or lupus, is a debilitating autoimmune disease characterized by the presence of an array of autoantibodies, including antibodies to dsDNA, to nuclear antigens and to ribonucleoproteins. SLE affects approximately 1 in 2000 individuals (U.S. 1 in 700 women). The disease primarily affects young women, with a female-to male ratio of approximately 9:1.
Systemic lupus can affect almost any organ or system of the body. Systemic lupus may include periods in which few, if any, symptoms are evident (“remission”) and other times when the disease becomes more active (“flare”). Most often when people mention “lupus,” they are referring to the systemic form of the disease.
Corticosteroids are the mainstay in treating systemic autoimmune disorders. Life threatening, severely disabling manifestations of SLE are treated with high doses of glucocorticoids (1-2 mg/kg/day). Undesirable effects of chronic glucocorticoids include an array of prominent adverse effects such as cushingoid habitus, central obesity, hypertension, infection, capillary fragility, hirsutism, accelerated osteoporosis, cataracts, diabetes mellitus, myopathy and psychosis. In addition to corticosteroid toxicity, patient compliance to a dosage regimen also poses a serious problem.
Cytotoxic agents are also used for controlling active disease, reducing the rate of disease flares, and reducing steroid requirements. Undesirable side effects of the latter include bone marrow depression, increased infections with opportunistic organisms, irreversible ovarian failure, alopecia and increased risk of malignancy.
SLE is an inflammatory disease for which to date there is no definitive treatment or cure. The disease results in acute and chronic complications. The only treatments available are palliative, aimed at relieving acute symptoms and preventing chronic complications, often with profound side effects. There is therefore an unmet need in this field, and both physicians and patients would welcome new treatments which could potentially eliminate or reduce the unwanted manifestations of the disease.
Peptides based on the complementarity-determining region of the human monoclonal anti-DNA 16/6Id antibody capable of immunomodulating SLE associated responses have been disclosed in PCT International Publication No. WO 02/067848 A2, the entire contents of which are hereby incorporated by reference. In particular, region CDR1 was found to inhibit the proliferative response of peripheral blood lymphocytes (PBL) of SLE patients to the human anti-DNA 16/6Id mAB, and to ameliorate disease manifestations of mice afflicted with spontaneous or experimental SLE.
Human CDR1, Shown in FIG. 1, is a synthetic peptide of 19 amino acids based on the complementarity-determining region (CDR1) of the human anti-dsDNA mAb denoted 16/6 Id, (SEQ ID NO: 1) (Waisman, A., et al. “Modulation of murine systemic lupus erythematosus with peptides based on complementarity determining regions of pathogenic anti-DNA monoclonal antibodies.” Proc. Nati. Acad. Sd. U.S.A. (1997), 94(4):4620-4625.
In experimental SLE models—Balb/c mice and SLE-prone mice, i.e. (NZBxNZW)F1 mice—treatment with either mCDR based-peptides or Compound 1 significantly reduced the SLE related findings, notably immune complex deposits (ICD) in the kidney, proteinuria and leukopenia. The treatment had no effect on the 16/6 Id specific antibody response (Waisman, A., et al. “Modulation of murine systemic lupus erythematosus with peptides based on complementarity determining regions of pathogenic anti-DNA monoclonal antibodies.” Proc. Natl. Acad. Sci. U.S.A. (1997), 94(4): 620; Eilat, E., et al., “Prevention of systemic lupus erythematosus-like disease in (NZBxNZW)F1 mice by treating with CDR1- and CDR3-based peptides of pathogenic autoantibody” J. Clin. Immunol. (2000), 20: 268; Eilat, E., et al., “The mechanism by which a peptide based on complementarity determining region-1 of pathogenic anti-DNA antibody ameliorates experimental SLE” (2001), Proc. Natl. Acad. Sci. U.S.A. 98: 1148).
These peptides, like many peptides, are not very soluble.
Therefore, formulations that improve the solubility of the peptides are desired.